The present invention relates to a pressure transducer with a sensing element made of a ceramic material and having a contour exhibiting rotational symmetry, and more particularly the invention relates to a pressure transducer with a rotationally symmetrical pressure sensor element of ceramic with a front face configured as a membrane, a housing which is of a pot-like configuration and embraces the pressure sensor, the housing being also configured in a rotational symmetry and the transducer further includes a sealing ring between the membrane and the base part of the housing.
A pressure transducer of the kind to which the invention pertains is basically known through German Printed Petty--Patent or Utility Model 89 14 010. It indeed includes a pressure sensor made of a ceramic material, having rotational symmetry and being contained in a housing that is provided with a rotational symmetrical base part and a pot or cup like configuration reaching beyond and around the side walls of this base part. The front face of the pressure sensor is configured as a membrane, and between it and the base part of the housing is provided a sealing ring more or less covering the edges of the pressure sensor. The sealing ring is to prevent penetration of the process material into the interior of the housing. The process material will appear, for instance, in a space between the front of the pressure sensor (i.e. the membrane) and the base part of the housing, but should not propagate any further. The presence of the gas, or more generally, pressure medium at that location adjacent to the membrane was needed in order to obtain a measuring response of the transducer, but the gas should be kept away from other equipment. A particular problem arises if the pressure sensor is provided with a surface of relatively coarse texture. Here, then, sealing may not be adequate.